A vulnerability in OP-TEE version 4.5.0 permits a local attacker to cause a denial of service in Trusted Applications by manipulating secure storage operation return codes.

The flaw exists due to improper handling of exceptional conditions (CWE-755) where secure storage operation return codes are passed unsanitized from the Rich Execution Environment (REE) to the Trusted Execution Environment (TEE). An attacker with low privileges in the REE can replace the tee-supplicant process to inject unexpected response codes, forcing Trusted Applications to panic.

The ability to force a panic in Trusted Applications results in a denial of service for critical secure services running within the TEE. Given the CVSS score of 7.9, this vulnerability represents a significant risk to system stability and the integrity of secure storage operations, potentially impacting the confidentiality and availability of sensitive data managed within the TrustZone environment.

Immediate Action: Update the OP-TEE optee_os component to a version that includes the fix provided in commit 941a58d78c99c4754fbd4ec3079ec9e1d596af8f.

Proactive Monitoring: Monitor system logs for unexpected application crashes or repeated service restarts originating from TEE-related processes.

Compensating Controls: Restrict access to the REE userspace and enforce strict process execution policies to prevent unauthorized users from replacing the tee-supplicant binary.

Public Exploit Available: Unknown.

This vulnerability presents a credible threat to the stability of the Trusted Execution Environment. Organizations utilizing OP-TEE 4.5.0 should prioritize the application of the upstream patch to prevent potential denial of service attacks. Failure to address this could lead to the compromise of critical secure storage functions.